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authorNamhyung Kim <namhyung@kernel.org>2022-03-28 23:01:12 +0300
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2022-04-13 21:59:24 +0300
commitfcf9ccf9d26a13d4a10ee6b167e429d96db97fe4 (patch)
treedf4fde69c5e69774c04f37f53dda0b4e41fc6ad7 /kernel
parent0309f053ce47721aed7987ad8048d7862235a61d (diff)
downloadlinux-fcf9ccf9d26a13d4a10ee6b167e429d96db97fe4.tar.xz
perf/core: Inherit event_caps
commit e3265a4386428d3d157d9565bb520aabff8b4bf0 upstream. It was reported that some perf event setup can make fork failed on ARM64. It was the case of a group of mixed hw and sw events and it failed in perf_event_init_task() due to armpmu_event_init(). The ARM PMU code checks if all the events in a group belong to the same PMU except for software events. But it didn't set the event_caps of inherited events and no longer identify them as software events. Therefore the test failed in a child process. A simple reproducer is: $ perf stat -e '{cycles,cs,instructions}' perf bench sched messaging # Running 'sched/messaging' benchmark: perf: fork(): Invalid argument The perf stat was fine but the perf bench failed in fork(). Let's inherit the event caps from the parent. Signed-off-by: Namhyung Kim <namhyung@kernel.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: <stable@vger.kernel.org> Link: https://lkml.kernel.org/r/20220328200112.457740-1-namhyung@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'kernel')
-rw-r--r--kernel/events/core.c3
1 files changed, 3 insertions, 0 deletions
diff --git a/kernel/events/core.c b/kernel/events/core.c
index 62022380ad8d..699446d60b6b 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -11596,6 +11596,9 @@ perf_event_alloc(struct perf_event_attr *attr, int cpu,
event->state = PERF_EVENT_STATE_INACTIVE;
+ if (parent_event)
+ event->event_caps = parent_event->event_caps;
+
if (event->attr.sigtrap)
atomic_set(&event->event_limit, 1);